Boat rudder with planing angle trim plates



Feb. 11, 1964 w. w. CHEW ETAL 3,120,829

BOAT RUDDER WITH PLANING ANGLE TRIM PLATES Filed Dec. 12, 1961 2 Sheets-Sheet 1 INVENTORS W LSON W. CHEW WILLIS G. STEWART ATTORNEYS Feb. 11, 1964 w. w. CHEW ETAL 3,120,829

BOAT RUDDER WITH PLANING ANGLE TRIM PLATES Filed Dec. 12, 1961 2 Sheets-Sheet 2 INVENTOR. WILSON W. CHEW WILLIS G. STEWART ATTORNEYS United States Patent 3,120,829 BOAT RUBBER WITH PLAYING ANGLE TRIM PLATES Wilson W. Chew, Barrington, and Willis G. Stewart,

Portsmouth, R.I., assignors to The Anchorage, Inc., a

corporation of Rhode Island Filed Dec. 12, 1961, Ser. No. 158,859 4 Claims. (Cl. 114-162) This invention relates to a rudder for a boat, more particularly a boat having mechanical propulsion.

It is known that the propeller of a propeller driven boat tends to draw the stern of the boat downwardly in a certain ratio to the power applied to the propeller, and this results in the raising of the bow as the stern is drawn downwardly. Boats which are to have relatively high propulsion are frequently given a wide supporting surface at the stern in the design of the hull. Also in some hulls the position of the weight carried is of importa'nce and varies with the number of people in the hull. However, the hull is of a fixed shape and cannot be altered for varying conditions.

One of the objects of this invention is to provide a means of controlling the position of the stern relative to the surface of the water through which the hull is passing so as to adjust the horizontal trim of the hull.

Another object of this invention is to utilize the forward movement of the vessel in providing for the means for trimming the hull to the desired horizontal position.

A still further object of the invention is to utilize the location of the greatest movement of water relative to the hull which is ordinarily about the rudder for employing greatest efliciency in the means for providing the desired horizontal trim of the hull.

Another object of the invention is to provide a trim mechanism which may be adjusted with reference to the propeller action especially as the axis of the propeller may be inclined to the horizontal in a vertical plane.

Another object of the invention is to provide for the adjustment of the trim of the hull through or in conjunction with the rudder steering column.

Another object of the invention is to provide an arrangement so that the area of the rudder which has the greatest effect on the planing angle of the boat may be selected for the trim control as occasion may dictate.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

FIGURE 1 is a fragmental view of the stern of a boat equipped with the rudder and the trim plates attached to the rudder in accordance with this invention;

FIGURE 2 is a fragmental elevational view partly in section showing the rudder, trim plates and actuating mechanism;

FIGURE 3 is a section on line 3-3 of FIGURE 2 of a portion of the structure there shown;

FIGURE 4 is a section on line 44 of FIGURE 2;

FIGURE 5 is a fragmental view illustrating the connection between the rudder post or steering column and a means for actuating the adjusting rod for the trim plates;

FIGURE 6 is a fragmental elevational view showing a modified means of connecting the adjusting rod to the trim plates;

FIGURE 7 is a sectional view on a larger scale illustrating an alternate arrangement of adjusting the rod which is attached to the trim plates;

FIGURE 8 is an elevation somewhat diagrammatic illustrating the relation of the rudder to a propeller shaft 3,129,829 Iatented Feb. 11, 1964 so as to show the effect of the adjustment of the pivot point of the trim plates;

FIGURE 9 is an elevation of a trim plate with an attachment added thereto to increase its surface area;

FIGURE 10 is a top plan view of the trim plate of FIGURE 9;

FIGURE 11 is a schematic view of a fluid manipulating arrangement for actuating the trim plate;

FIGURE 12 is a fragmental sectional view of a variation of FIGURE 11;

FIGURE 13 is a schematic view of a modified electrical actuating means for the trim plates; and

FIGURE 14 is a schematic view of an arrangement for actuating twin rudder trim plates simultaneously.

In proceeding with this invention, we have provided a tubular post attached to the rudder for swinging the same about the axis of the post and through this post have passed a rod which is attached to a pair of plates extending laterally from the rudder and pivoted near the trailing edge of the rudder so that movement of the rod axially of itself and the post will swing the plates for adjusting their position, which in turn will adjust the horizontal trim of the boat as it passes through the water.

We also provide for varying the point of pivoting of the trim plates so that they may be adjusted with reference to a propeller, especially in a situation where the propeller shaft is at an angle to the horizontal and has a somewhat downward thrust, and we also provide for an arrangement by which the area of the pivot trim plates may be changed.

ith reference to the drawings, 1t) designates generally a boat or vessel having a transom 11, a skeg or keel 12 and a rudder 14 to the forward or leading edge of which is attached a steering post 15 which may rotate in bearings about its axis so as to swing the rudder for guiding the vessel or boat. This rudder usually has a mounting pin 16 at its lower edge 34 in a bearing 17 on the after edge of the skeg or keel 12, and this post may be variously manipulated by means of a quadrant or sheave Within the boat and the usual steering mechamsm.

A pair of trim plates 2% and 21 are provided with flanges 22 at their inner edges extending lengthwise of the trim plates the full length thereof. These flanges 22 as shown in FIGURE 4 are provided with openings 23 which register with an opening 24 in the rudder, and a pin 25 passes through these openings so as to pivotally mount the flanges 22 of each of the trim plates 20, 21 on opposite sides of the rudder 14. A washer 55 is positioned between each flange 22 and the rudder as shown. The pin 25 is reduced as at 26 at either end and there threaded. Washers 27 engage shoulders 28 provided by the reduced portions, while nuts 29 engaging lock washers 30 are screwed up tight against the washers 27 so as to hold the pin in position. The shoulders prevent binding of the securing nuts against the flanges 22, thus leaving them free to pivot upon the pin 25. This pin 25 is located near the trailing edge 31 of the rudder 14 and at a point on the rudder near its upper edge 32. These trim plates extend upwardly at a slight angle such as shown in FIGURE 3 as they progress laterally outwardly from the rudder 14. This angle is about 1 0, although it may be varied somewhat and is useful at the time of turning of the boat sharply, during banking of the hull against the water.

The steering column 15 is provided with a coupling 35 (see FIGURES 2 and 3) at its lower end which is slotted to receive the upper edge 32 of the rudder therein and is secured to the upper edge of the rudder near the leading edge 33 by welding so as to attach the steering post 15 c Q fixedly to the rudder so that turning of the steering post will turn the rudder.

Passing through this steering post, there is a rod 36 which is bifurcated at its lower end providing arms 37 which straddle the upper edge 32 of the rudder and extend along its opposite sides. At the lower end of each of these arms 37, there is a trunnion 38 which extends outwardly from its opposite sides and passes through a slot 39 in the forward edge of the flange 22 of the trim plates 20 and 21 so as to secure it to the trim plates. This slot 39 is sufiicient in length so that as the rod 36 is moved axially up and down in the steering post 15, it will accommodate movement upwardly and downwardly of the trim plates from a horizontal position. Each of the trunnions 38 are provided with a hole through which a cotter pin 49 passes so as to secure the trunnions to the trim plates.

As an alternate to providing a bifurcated end on the rod 36, the rudder may be slotted as at 41 as shown in FIGURE 6, and the rod 36 may be provided with a cross pin 42 extending th ough its ends and extending into slots in the flanges 22 of the trim plates 23 and 21. This post may be secured to the rudder 14 at such location as may be desired in order to obtain a balancing effect forwardand aft of tie axis of the post as design requirements may require.

Adjustment of the trim plates is by axial movement of the rod 36, and this may be accomplished by the use of a drum 45 having a bottom Wall 46 (see FIG. 2 and also FIG. lhlCll threadingly engages the threads 47 on the upper end of the post so that rotation of this drum by means of a flexible cable 48 will cause the drum to move axially of the steering post 15. The upper head .49 of this drum receives the reduced portion 5! of the rod 36 on a shoulder 51 so as to be freely rotatable thereon. The upper head 4% is prevented from being lifted off the reduced portion 5%) by a locking nut 52 beneath which there is a washer 53. The nut does not bind on the head 49.

In some cases the tubular post 15 as seen in FIGURE .7 receives the rod 56 in place of the rod 36 slidably fitted therein, which rod is threaded as at 57 at its upper portion. A bevelled gear 58 is mounted on the tubular post 15 by means of snap rings 59 and 60 so as to be freely rotatable thereon, and this gear carries a cap 61 bolted thereto by bolt 62 which cap is threaded as at 63 to engage the threads 57 on the rod 56. Thus as the gear turns, the rod 56 will be lifted or lowered through the post 15 depending upon the direction of rotation of the-gear 58 on the post 15. Some sort of a guide bearing 64 will rotatably mount the post 15 on the transom 11 of the boat. A bracket 65 is fixed on the post 15 as at 66 so that turning of this bracket will also turn the post, and this bracket rotatably mounts a tiller 67 in the bearing 68 in the bracket. At the end of this tiller there is fixed a bevelled gear 69 which meshes with the gear 53 so that rotation of the tiller 67 will rotate the gear 58 and move the rod 56 vertically in the steering column or post 15 whereas swinging the tiller 67 will swing the post 15 in its bearings so as to turn the rudder for guiding this vessel.

In some cases where the propeller shaft 70 is inclined as shown in FIGURE 8 so that the propeller 79 has a downward thrust, it is desirable to provide an adjustable pivotal mounting for the trim plates and 21, and as seen in FIGURES 2 and 8, this may be accomplished by a plurality of openings 71, 72, 73 and 74 in addition to the opening 24 above referred to, in any one of which the pivotal mounting for the plates may be positioned, while the rod for adjusting these plates will remain the same as heretofore described and may be shown as the rod 36 or the rod 56.

In some cases it may be desirable to increase the size of the fin, and as shown in FIGURES 9 and 10, we have illustrated a fin 2%) which has a reduced portion at its trailing edge as at 75 while an added section 76 having a notched edge to fit this reduced portion may be positioned thereon and be held by bolts '77 with their heads recessed so as to provide a smooth upper surface as may be seen in FIGURE 9. These extensions such as 76 may be of varying sizes so that the desired area may be selected.

From the above it will be apparent that the rod 36 is adjusted axially for moving the trim plates at their inboard ends, and while this rod is shown as being mechanically actuated, various means of moving the rod axially may be utilized including many different power sources, such for instance as electrical, hydraulic or pneumatic including either pressure or vacuum. It will also be readily apparent that if two or a plurality of rudders were used that the control mechanisms for shifting the trim plates upon more than one rudder might be linked together so that the trim plates could be operated in unison.

In FIGURE 11 we have illustrated a hydraulic means of effecting the axial shifting of the rod 36. Here the rod 36 is shown as provided at its upper end with a piston Si) in a cylinder 81. This cylinder is connected in a hydraulic system to a master cylinder 82 which has a piston 83 therein which may be operated through piston rod 84 by a lever 35. A tube 86 connects one end of cylinder 82 to one end of cylinder 81, while a tube 87 connects the other ends of these cylinders. Thus by moving the lever 85, the master piston 83 will move in the cylinder and cause a corresponding movement of the slave piston 88 to actuate the rod 36 for changing the elevation of the trim plates on the rudder 14. In some cases as shown in FIG. 12, a cylinder may have a piston 96 urged in one direction by spring 97, while fluid means under pressure may serve to enter above the piston through conduit 93 to force the piston and the rod 36 connected thereto downwardly.

In the diagrammatic view shown in FIG. 13, a reversible motor 88 is connected to a switch 3 9 which may engage either contact'% or 91 so as to cause energization of the motor to rotate in one direction or the other. The shaft extending from this motor is connected to a gear such as 69 which in turn rotates gear .58 so as to turn the same in either direction for effecting movement of the rod 56 upwardly or downwardly (see FIG. 7) as may be desired.

In the event that two rudders are utilized, there may be'two drums such as shown in FIG. 2, only one of which is actuated by the cable 48, and on the upper ends of these two drums, there may be mounted gears-92 and 93 as seen in FIG. 14 which are connected together by a chain 94 so that upon rotation of one of the drums, the other drum will be correspondingly rotated and will cause movement of the rod 36 so that the elevating plates upon both rudders will be simultaneously operated.

We claim:

1. A boat rudder having a steering post with the rudder extending radially from the post, means for pivotally mounting the steeringpost about a generally vertical axis, trim plates carried by the rudder and located on each side thereof, said trim plates being inclined upwardly as they progress away from the rudder, and means coaxial of said axis for moving the trim plates relative to the rudder.

2. A boat rudder as in claim 1 wherein means are provided to selectively pivot the trim plate at various locations.

3. A boat rudder, a hollow post secured to the forward edge of the rudder for pivotally mounting the rudder to swing about the axis of said post, trim plates extending laterally from each side of the rudder and with their trailing ends pivoted thereon adjacent the trailing edge of the rudder, a rod passing through said post and attached to the leading end of the plates, a drum having threaded engagement with said post for axial movement thereon when rotated, said drum being swivelly attached to said rod whereby rotation of said drum axially moves said rod and in turn swings said plates relative to the rudder about their pivot thereon.

4. A boat rudder, a hollow post secured to the forward edge of the rudder for pivotaliy mounting the rudder to swing about the axis of said post, trim plates extending laterally from each side of the rudder and with their trailing ends pivoted thereon adjacent the trailing edge of the rudder, a rod passing through said post and attached to the leading end of the plates, a gear having threaded engagement with the post for axial movement thereon when rotated, said gear being swivelly attached to said rod whereby rotation of said gear axially moves said rod and in turn swings said plates relative to the rudder about References Cited in the file of this patent UNITED STATES PATENTS 2,705,468 Dix Apr. 5, 1955 3,001,502 Stoker Sept. 26, 1961 FOREIGN PATENTS 91,234 Norway Mar. 17, 1958 683,438 Great Britain Nov. 26, 1962 

1. A BOAT RUDDER HAVING A STEERING POST WITH THE RUDDER EXTENDING RADIALLY FROM THE POST, MEANS FOR PIVOTALLY MOUNTING THE STEERING POST ABOUT A GENERALLY VERTICAL AXIS, TRIM PLATES CARRIED BY THE RUDDER AND LOCATED ON EACH SIDE THEREOF, SAID TRIM PLATES BEING INCLINED UPWARDLY AS 